Today’s article is a guest post from Konstantin Monastyrsky of GutSense.org. In keeping with the mission statement of Mark’s Daily Apple to investigate, discuss, and critically rethink everything we’ve assumed to be true about health and wellness, I like to periodically give credible researchers who are challenging conventional wisdom the opportunity to share their insights and findings here. It’s a great way to open a dialogue on topics that deserve challenging. Like fiber, for instance. Everyone knows that fiber is good for you, right? Well, let’s find out what Konstantin—a guy who’s spent an incredible amount of time researching this topic—thinks about this truism. Enter Konstantin…

Does dietary fiber contain anything of nutritional value? No, it doesn’t. Zero vitamins… Zero minerals… Zero protein… Zero fat… Nothing, zilch, not even digestible carbohydrates. Why, then, is it considered a healthy nutrient? As the story goes, you can thank Dr. John Harvey Kellogg for that:

“Dr. Kellogg was obsessed with chastity and constipation. True to principle, he never made love to his wife. To “remedy” the sin of masturbation, he advocated circumcision without anesthetic for boys, and mutilation of the clitoris with carbolic acid for girls. He blamed constipation for “nymphomania” in women, and lust in men, because, according to Kellogg, impacted stools inside one’s rectum were stimulating the prostate gland and the female vagina into sexual proclivity.” [link]

To fix these “ailments,” Dr. Kellogg was prescribing a coarse vegetarian diet along with 1 to 3 ounces of bran daily, and mineral oil with every meal. As any nutritionist will tell you, the decline of libido and infertility are among the very first symptoms of malnutrition prevalent among ardent vegans. And in this particular case, extra bran and mineral oil were “enhancing” damage by blocking the assimilation of nutrients from an already meager diet.

And what was Dr. Kellogg’s rationale for prescribing mineral oil? Well, because so much fiber was enlarging stools, intense straining was required to expel them. The oil was used as a lubricant to reduce pain caused by straining, and to prevent bloody anal fissures inside the anal canal.

However, the ultimate fame and money came to Dr. Kellogg not from crusading against sex, but from ready-to-eat morning cereals after he found that baking bran into cereals proved to be incredibly profitable for Kellogg Company. From that point on, it took another sixty years or so of relentless brainwashing to turn what once used to be a dirt-cheap livestock feed into a premium health food.

Well, that’s an old story, and I can understand if you doubt it—it sounds too incredulous to be true! So, let’s debunk fiber’s mythology with facts and science. Here we go, one myth at a time:

Reality: Here is how many fresh fruits you’ll need to eat throughout the day in order to obtain those 30 to 40 grams (1-1.4 oz.) of daily fiber:

As you can see, that comes to five apples, three pears, and two oranges. A small apple contains 3.6 g of fiber and 15.5 g of sugars. A small pear—4.6 g and 14.5 g; and a small orange—2.3 g and 11.3 g, respectively (USDA National Nutrient Database; NDB #s: 09003; 09200; 09252 [link]).

These ten small (not medium or large) fruits will provide you with 36.4 g of indigestible fiber and a whopping 143.6 g of digestible sugars, or an equivalent of that many (ten) tablespoons of plain table sugar!

And that‘s before accounting for all the other carbs consumed throughout the day for breakfast, lunch, dinner, and from snacks and beverages.

So ask yourself this question: even if you are a 100% healthy 25-year-old muscle-bound athlete, would you ever ingest that much sugar willingly? Well, maybe under the influence of a controlled substance or torture…

But that’s exactly what’s being recommended for “health purposes” to children and adults. It‘s not surprising that so many Americans are suffering from the ravages of diabetes and obesity—a moderately active adult can utilize no more than about 200 grams of carbohydrates per day without encountering a scourge of the inevitable obesity, prediabetes, or diabetes.

The ratio of digestible carbohydrates (sugars) to fiber in vegetables, cereals, breads, beans, and legumes is, on average, similar to fruits. Thus, no matter how hard you try to mix’n’match, you’ll be getting harmed all the same.

Please do note that if you are healthy, active, and normal weight, there is nothing wrong with consuming fruits and vegetables in moderation. The point of this section is to impress on you that it is NOT OK to binge on fruits to ingest recommended daily intake of fiber.

This myth—that fruits and vegetables are the best source of dietary fiber—is probably the most pervasive and damaging of all. If 30 grams of fiber is what you’re really after, you’re better off getting it from supplements. These, after all, have almost no digestible carbs. But, then, of course, you run into those other persistent falsehoods…

Reality: That’s a blatant deception. If you consume 100 g of plain table sugar at once, the blood absorbs all 100 g of sugar almost as soon as it reaches the small intestine, where the assimilation takes place. If you add 30 g of fiber into the mix, the fiber may extend the rate of sugar assimilation into the blood, from, let‘s say, one hour to three.

But at the end of those extra three hours the blood will still absorb exactly the same 100 g of sugar—not an iota more, not an iota less. If you are a diabetic, the only difference will be that you‘ll require more extended (long-acting) insulin for type 1 diabetes, or larger doses of medication for type 2 diabetes in order to deal with slow-digesting sugars, and your blood glucose test will not spike as high after the meal.

But you‘re fooling no one but a glucose meter. In all other respects, the damage will be all the same, or even worse. And that‘s even before taking into account the negative impact of fiber on the digestive organs, or hyperinsulinemia and triglycerides on the heart, blood vessels, and blood pressure.

Reality: Fiber indeed slows down the “digestive process,” because it interferes with digestion in the stomach and, later, clogs the intestines the “whole nine yards.” The myth is that it can be good for health and the digestive process.

Here is what you get from delayed digestion: indigestion (dyspepsia), heartburn (GERD), gastritis (the inflammation of the stomach‘s mucosal membrane), peptic ulcers, enteritis (the inflammation of the intestinal mucosal membrane), and further down the chain, constipation, irritable bowel syndrome, ulcerative colitis, and Crohn‘s disease.

All this, in fact, is the core message of Fiber Menace: fiber slows down the digestive process! And slow digestion is ruinous for your health. Don‘t mess with fiber unless your gut is made of steel!

Myth #4: Fiber speeds food through the digestive tract, helping to protect it against cancer.

Reality: Not true. In fact, this claim directly contradicts the claim that fiber-rich foods slow down the digestive process. For a reality check, here’s an excerpt from a college-level physiology textbook that reveals the truth:

“Colonic Motility: Energy-rich meals with a high fat content increase motility [the rate of intestinal propulsion]; carbohydrates and proteins have no effect.”

The excerpt below comes, of all places, from the Harvard School of Public Health:

Fiber and colon cancer

“For years, Americans have been told to consume a high-fiber diet to lower the risk of colon cancer—mainly on the basis of results from relatively small studies. Larger and better-designed studies have failed to show a link between fiber and colon cancer.”

“Based on its review of the scientific evidence, FDA finds that (1) the most directly relevant, scientifically probative, and therefore most persuasive evidence (i.e., randomized, controlled clinical trials with fiber as a test substance) consistently finds that dietary fiber has no [preventive] effect on incidence of adenomatous polyps, a precursor of and surrogate marker for colorectal cancer; and (2) other available human evidence does not adequately differentiate dietary fiber from other components of diets rich in foods of plant origin, and thus is inconclusive as to whether diet-disease associations can be directly attributed to dietary fiber. FDA has concluded from this review that the totality of the publicly available scientific evidence not only demonstrates lack of significant scientific agreement as to the validity of a [preventive] relationship between dietary fiber and colorectal cancer, but also provides strong evidence that such a relationship does not exist.”

Alas, the story doesn’t end there. Adding insult to injury, Chapter 10 of my book entitled Fiber Menace, “Colon Cancer” cites studies that demonstrate the connection between increased fiber consumption and colon cancer. Also, countries with the highest and lowest consumption of meat are compared. Not surprisingly, the countries with the lowest consumption of meat and, correspondingly, the highest consumption of carbohydrates, including fiber, have the highest rate of digestive cancers, particularly of the stomach.

Myth #6: Fiber offers protection from breast cancer.

Reality: A blatant, preposterous lie. According to the recent massive study jointly conducted by the U.S. Center for Disease Control and Prevention, the Ministry of Health of Mexico, and the American Institute for Cancer Research, it’s the opposite: women with the highest consumption of carbohydrates, and, correspondingly, of fiber, had the highest rates of breast cancer:

Carbohydrates and the Risk of Breast Cancer among Mexican Women

“In this population, a high percentage of calories from carbohydrate, but not from fat, was associated with increased breast cancer risk.”

Although this study has singled out carbohydrates as the culprit behind various cancers, where there’s smoke, there’s also fire: carbs and fiber are as inseparable as Siamese twins, as I have already explained in Myth #1.

The myths about fiber’s role in coronary heart disease (CHD) and the management of elevated cholesterol have their roots in some dubious research, which culminated in “reduced mineral absorption and myriad of gastrointestinal disturbances” after the study participants were given supplements containing a mixture of guar gum, pectin, soy fiber, pea fiber, and corn bran along with a low-fat and reduced cholesterol diet.

The total reduction of LDL cholesterol after 15 weeks was from “7% to 8%”. As any cardiologist will tell you, the reduction of “bad” cholesterol from, let’s say, 180 to 166 mg/dL (-8%) is completely meaningless. Besides, if you cause someone to have a “myriad of gastrointestinal disturbances” in the process, that person is more likely to die prematurely from malnutrition and cancer than of stroke or heart attack.

Even then, this marginal reduction of cholesterol had little to do with fiber, and everything to do with the reduction of dietary fats. LDL cholesterol happens to be a major precursor to bile. The moment a person is placed on a low-fat diet, their cholesterol level drops because their liver no longer needs to produce as much bile.

In addition, intestinal inflammation caused by soluble fiber blocks the ability of bile components to get absorbed back into the bloodstream, further lowering the cholesterol level. This is as basic as the physiology of nutrition gets, and it makes the whole claim of a fiber-cholesterol connection a deliberate con.

There is another dimension to the con used to “prove” fiber‘s role in reducing cholesterol. Most of the studies on fiber’s cholesterol-lowering effect—particularly psyllium—used The American Heart Association’s (AHA) Step 1 diet.

The Step 1 diet is high in carbohydrates and low in fat by design, with less than 10% of total energy derived from saturated fat. During clinical studies among people using the Step 1 diet without added fiber, their total cholesterol fell by 8%, LDL cholesterol fell by 6%, and HDL cholesterol fell by 16%.

In other words, the Step 1 diet on its own, without any extra fiber and/or digestive side effects, demonstrates an almost identical drop in cholesterol as with added fiber. In legalese, this particular “coincidence” is called fraud, plain and simple.

So one fraud more, one fraud less…what‘s the worry, if my cholesterol goes down?

Well, there is a legitimate worry, at least, according to this respected source:

Problem with American Heart Association “Step 1″ diet

“Although the AHA Step 1 diet decreased total and LDL cholesterol levels in this group of women, it decreased HDL cholesterol by an even greater proportion. In women, a low HDL cholesterol concentration is a stronger independent predictor of cardiovascular disease risk than is elevated total cholesterol or LDL cholesterol. Therefore, women who follow AHA guidelines for lowering their serum cholesterol may actually be increasing their risk of heart disease”

Amazingly, back in 2001, the AHA replaced the Step 1 diet with the Step II, TLC, and ATP III diets [link], which are even more restrictive in terms of fat, and even more permissive in terms of carbohydrates.

And don’t get me started on triglycerides… First, nothing raises triglycerides as profoundly as a high-fiber diet does, because, paraphrasing the smoke-fire cliché, where there’s fiber, there’re carbohydrates, usually eight to ten times as much.

This fact—the more fiber you consume, particularly from natural sources, the higher your level of triglycerides from carbohydrates intake—has been dodging Dr. Dean Ornish [link] one of the most prominent proponents of a high-carb/high-fiber diet.

Second, once inside the colon, fiber itself gets fermented by intestinal bacteria. Among the byproducts of bacterial fermentation are short-chain fatty acids—butyrate, acetate, and propionate. Most of these fatty acids get assimilated directly into the bloodstream to provide energy.

According to the Dietary Reference Intakes manual “current data indicate that the [energy] yield is in the range of 1.5 to 2.5” calories per each gram of consumed fiber [link]. If you aren’t starving, the absorbed fatty acids unused for energy get metabolized by the liver into triglycerides for further storage as body fat.

Granted, a few calories here, a few calories there, may not seem like a lot. Still, if you are consuming 30 to 40 grams of fiber daily plus whatever “hidden” carbohydrates you are ingesting unknowingly along with processed food, it all adds up to epidemics of obesity, diabetes, and heart disease.

Myth #8: Fiber satisfies hunger and reduces appetite.

Reality: When the scientists from the Human Nutrition Research Center on Aging at Tufts University decided to look at this dubious claim, here is what they have found out:

Fermentable and Nonfermentable Fiber Supplements Did Not Alter Hunger, Satiety or Body Weight in a Pilot Study of Men and Women Consuming Self-Selected Diets

“Despite the large total intakes of FF [fermentable fiber – ed.] and NFF [non-fermetable fiber – ed.] supplements, there were no significant changes in body weight or fat during consumption of either type of fiber, even among the subjects with higher BMI.”

And as you keep digging deeper, you soon realize that consuming too much fiber may actually contribute to obesity. Because fiber rapidly absorbs water and expands in the stomach up to five times its original size and weight, it indeed pacifies the appetite for a short while.

Myth #9: Fiber prevents gallstones and kidney stones.

Reality: I‘ve seen several observational studies that claim fiber can prevent gallstones. It isn‘t true. It‘s common knowledge that diabetes and obesity are consistently associated with higher risk for gallstones, and both of these conditions are the direct outcome of excessive consumption of carbohydrates, and correspondingly, of fiber. Beyond these few studies, there isn‘t a shred of physiological, anatomical, clinical, or nutritional evidence that connects gallstone formation with fiber consumption.

Here‘s an excerpt from Fiber Menace that sheds further light on the gallstone-fiber connection:

Fiber’s affect on the small intestine: Not welcome at any price

Gallstones are formed from concentrated bile salts when the outflow of bile from the gallbladder is blocked. […] before they can form, something else must first obstruct the biliary ducts. Just like with pancreatitis, that “something” is either inflammatory disease or obstruction caused by fiber.

Women (in the West) are affected by gallstones far more than men, because they are more likely to maintain a “healthy” diet, which nowadays means a diet that is low in fat and high in fiber. Since the gallbladder concentrates bile pending a fatty meal, no fat in the meal means no release of bile. The longer the concentrated bile remains in the gallbladder, the higher the chance for gallstones to form (from bile salts).

Just as with gallstones, kidney stones are also common among people who suffer from diabetes and obesity, because excessive consumption of carbohydrates increases the excretion of urine, changes its chemistry, and predisposes to kidney stones.

To investigate this myth further, I consulted PubMed, a service of the National Library of Medicine, which is the most thorough compendium of medical research. I reviewed eighty-one articles published between 1972 and 2005 (the year I was researching my book) that mention the words “fiber” and “kidney stones”. Not a single one of them connected kidney stones to fiber consumption, while several specifically pointed out that an increased consumption of carbohydrates is one of the major contributing factors.

One article suggested that a diet free of digestible carbs, but containing fiber, makes urine composition less stones-prone. You don‘t have to be Dr. Watson to deduce that fiber—an indigestible substance—can‘t materially affect urine chemistry, because what can‘t get digested also can‘t reach the kidneys. Besides, it wasn’t the presence of fiber that did the “trick,” for those investigators, but the reduction in digestible carbohydrates.

Myth #10: Fiber prevents diverticular disease.

For a while, it was difficult to disprove this absurdity by appealing to common sense. So I devoted a whole chapter inFiber Menace to explaining why fiber CAUSES diverticular disease. Thank God, I am no longer alone in this thinking:

Fiber Not Protective Against Diverticulosis

Contrary to popular medical wisdom, following a high-fiber diet has no protective effect against developing asymptomatic diverticulosis, according to a colonoscopy-based study presented at the 2011 Digestive Disease Week (DDW) meeting (abstract 275). In fact, the study showed that patients who ate more fiber actually had higher prevalence of the disease.

For decades, doctors have recommended high-fiber diets to patients at risk for developing the intestinal pouches, known as diverticula. The thinking has been that by keeping patients regular, a high-fiber diet can keep diverticula from forming. But the new study suggests the opposite may be true.

A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis

A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.

The only problem with all of the above research is that it may take another six to eight years to tell people what I was telling them eight years ago: if you wish to protect your gut from diverticular disease, keep fiber out of it.

Myth #11: Fiber is safe and effective for the treatment and prevention of diarrhea.

Reality: Actually, it’s the complete opposite—fiber, particularly soluble, is the most common cause of diarrhea in children and adults. That’s why it’s recommended as a laxative to begin with. The idea of fiber as a preventive treatment for diarrhea is one of the most preposterous and harmful fiber-related frauds.

These inexpensive industrial fillers are added as stabilizers and volumizers to practically all processed foods, because they hold water, maintain shape, and fake “fattiness.” Besides, they are cheaply bought by the ton, and are resold retail by the gram for immense profit.

Once inside the body, these fiber fillers remain indigestible, hold onto water just as tight, and prevent absorption. This property—the malabsorption of fluids—lies behind soluble fiber‘s laxative effect: under normal circumstances a very limited amount of fluids enter the large intestine. When their amount exceeds the colon’s holding capacity, you get hit with diarrhea.

In other words, the term “laxative” is just a euphemism for a “diarrheal” agent. If you overdose on a fiber laxative, you’ll end up with diarrhea. If you “overdose” on fiber from food, you’ll end up with exactly the same diarrhea. But since fiber in food can’t be measured as reliably as fiber in capsules, wafers, or powders, it’s much easier to “overdose” the latter fiber and cause severe diarrhea.

Besides, fiber is even more offensive than synthetic laxatives, because the byproducts of its fermentation cause intestinal inflammation, flatulence, bloating, and cramping—just as described in medical references:

Gastrointestinal Disorders; The Merck Manual of Diagnosis and Therapy [link]

The diarrheal effect of soluble fiber is particularly harmful for children, because their smaller intestines need lesser amounts to provoke diarrhea. According to the Centers for Disease Control and Prevention:

The Management of Acute Diarrhea in Children

…diarrhea remains one of the most common pediatric illnesses. Each year, children less than 5 years of age experience 20-35 million episodes of diarrhea, which result in 2-3.5 million doctor visits, greater than 200,000 hospitalizations, and 325-425 deaths.

These figures are from 1992, the latest statistic I could find. It must be much worse today because fiber is so much more prevalent. And if you analyze the most basic facts, you’ll understand immediately why this travesty is taking place. Consider this:

A single adult dose of Metamucil®—a popular fiber laxative made from psyllium seed husks—contains 2 g of soluble fiber in 6 capsules [link]. One apple, one orange, and one banana—not an unusual number of fruits a child may eat throughout the day—contain a total 4 g of soluble fiber, or an equivalent of 12 capsules of Metamucil for a much larger adult.

And that’s on top of all the juices, cereals, yogurts, ice creams, candies, cakes, and all other processed food consumed on the same day, all loaded with fiber as well. No wonder that “diarrhea remains one of the most common pediatric illnesses” in the United States, and there is an acute shortage of pediatricians nationwide.

Myth #12: Fiber relieves chronic constipation.

I left this myth for last because it is the most pervasive. For the same false reasons that people believe in the cleansing prowess of fiber, everyone and their uncle also believes that fiber relieves constipation.

Not quite true. According to the experts from the American College of Gastroenterology’s Functional Gastrointestinal Disorders Task Force, all legitimate clinical trials “…did not demonstrate a significant improvement in stool frequency or consistency when compared with placebo.” [link]

In plain English, it means fiber is no better at relieving constipation than a sugar pill. Indeed, how could it be, when fiber causes constipation in the first place! Again, I describe the exact reasons behind the fiber-constipation connection in Fiber Menace.

Even The Merck Manual of Diagnosis and Therapy, the very first book your doctor consults when needing up-to-date medical advice, has recently changed their tune regarding fiber, clearly the outcome of my work.

“Fiber supplementation is particularly effective in treating normal-transit constipation but is not very effective for slow-transit constipation or defecatory disorders” [link]

In plain English, it means the following: “Fiber supplements will catapult healthy people into a loo because of their laxative effect. But for anyone with a history of chronic constipation, they don’t work.”

Finally, consider the stern warnings, that accompany Metamucil, a fiber supplement made from psyllium:

So not only do fiber supplements not work for most people with chronic constipation, but they may also make them ill. Probably not ill enough to kill their libido as Dr. Kellogg originally intended, but imagine enjoying sex with your partner while being bloated and flatulent courtesy of extra fiber in your morning cereals.

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You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

Ok, I disagree with most of you. The point of the blog is that fiber is not the miracle cure all. IMHO, that was reasonably presented and documented.

If you do well on BAS, great. Show me evidence that Grok had a daily BAS.

Yes, I would like him to have distinguished between soluble and insoluble. He did say early in the blog that fruits and vegetables are fine in moderation. The blog didn’t come off as anti-veggie to me. I would point out, however, that there are many anti-veggie members of the forum. (I am not one of them.)

Hmmm..anti-veggie in what sense? I do eat vegetables. I like them, they are tasty with animal products. 😉 I just don’t think they’re necessary if you eat fresh, grass-fed meat with bone broth and organ meat. They strike me as a secondary nutrition source, not a primary one. Thus, I, at least, tend to react negativity when I hear about them as a sort of holy grail of health.

I agree that it wasn’t anti-veggie post, but I don’t see as particular persuasive either. I’ve *never* heard of fiber being used to treat diarrhea, ever. (Myth #12) My husband and I were struggling with a minor stomach bug last week and we deliberately skipped our normal vegetables and salads because of their known effects. That kind of inclusion tends to make me question the rest of the article.

I don’t know…he could have taken out about 6 myths and it would have been more compelling in my mind.

Thank you for this. I didn’t find this article to be hysterical or ranting. I too would have liked a distinction made between insoluble and soluble fiber, but this article had a narrower focus; he was discrediting various common myths about fiber. If he was emphatic in his tone, so what? He had good arguments as well as scientific sources to back them up.

Yes this guest author must be a total “quack”, with his challenging conventional wisdom, and use of PubMed to make a point. I cannot believe Mark didn’t run a background check on this guy. Did he even read his biography, or look at his “crazy” site? (Sarcasm)

I have personal experience with Fiber Menace and applying it to my own body. I’ll try and keep it brief and coherent.

I had poor digestive health since I was a kid and my diet was not helping. Half a year before I changed my diet I had terrible constipation. I went to a doctor and he prescribed fiber supplements. I tried and my stool eventually just became so big and dry that I couldn’t expel it one day and developed an anal fissure that had me bleeding for a few months after most bowel movements.

After I found fat head, things improved but not completely. I was still bleeding occasionally. I then found Fiber Menace and it rang true to me. The bad types of fiber were preventing the healing process by continually opening the wound (stool was too big/hard still). At that point I did a few things he details, I cut out ALL fiber and bought probiotic supplements. The probiotics were improving my gut flora and lack of fiber gave my fissure time to heal.

Eventually, I came to the conclusion that not all fiber is evil. I started introducing plant foods back in to my diet and I could tolerate small amounts, increasing over time. Certain foods actually made things better. Root vegies and fruits wouldn’t trigger anything but chocolate, wheat, legumes and the types of veggies like broccoli, cabbage and spinach would make things worse, the differences being the type of fiber!

So I don’t agree with Mr Monastyrsky entirely but there’s something to it. I believe if your gut health is compromised, insoluble fiber is one of the worst things you can do to it. Changing your gut microbiome is the real reason why I healed long term, but I needed to remove fiber for a year or so to allow things to settle.

Yes it is…to some extent. But there the similarity ends. Metamucil can also contain wheat flour, fructose, soy lecithin, ascorbic acid (preservative), sucrose, FD&C Yellow No. 6, plus a variety of other ingredients, any of which can aggravate IBS. Whole psyllium husks are completely natural and contain nothing else. Taken according to directions, it can be helpful for both IBS-D and IBS-C.

I agree with others who have said they don’t like the aggressive, tirading tone of this article. My biggest complaint about it, though, is that it implies — DESPITE the disclaimer that normal people don’t need to restrict veggies — that vegetables are somehow not good for you, or not important in the diet. But I just don’t see this played out in reality. Obviously Kellogg was a nut, but it is a false choice that either we embrace him or reject the whole idea of fiber as having any nutritional value whatsoever. The author clearly has an axe to grind, and makes some perhaps valid points about the degree to which fiber has been wrongly touted as a fix for various health problems, but he does so at the expense of recognizing other aspects of the story — that fiber-containing foods have many health benefits. It’s just not that simple, and as others have remarked, I am glad to see that people don’t accept what seems like some oversimplification going on with this piece.

I’m glad this got covered since it’s too popular to ignore, but “fiber is bad” is way too simplistic for the crowd on MDA. We know that there are all sorts of things in plant foods, not just carbs and fiber. Whole wheat, white rice, broccoli, and apples are all very different foods.

Just read Kellogg’s bio on Wikepedia. Wow, “freak” doesn’t begin to describe it. But he and his brother (also a vegetarian) both lived to 91, which, considering how he lived, must’ve been a very long life indeed.

Resistant Starch is a filler? Butyrate is bad for you? All forms of fiber are the same? WTF?

Undercooked, or cooked and then cooled tubers – potatoes, cassava/tapioca root, yams, carrots, etc. These are all things that Grok would have eaten. These have what’s called “retrograded starch” which is a “resistant starch” which is a form of fiber and a prebiotic. Are we supposed to believe that this is not natural, and is not healthy?

This article is garbage and Sisson should be ashamed to post it. Mark, this is an advertisement that you got paid for right? Please tell me yes, otherwise this makes no sense.

I usually love reading the daily posts and comments from this site. But holy geeze, today a number of people commenting sound like evangelical followers of Grok. This post has done a great job of sparking debate within the primal circle; for that we should be thankful. I have much gratitude for the MDA team for bringing new perspectives to the board, we all need to reevaluate our perspectives once and a while ;).

Pretty much all of the issues I had with this posting have been addressed, the tone is a bit alarmist, the fruit part, etc. But I wouldn’t go as far to say that I’m disappointed, particularly with Mark’s comment that he’d post a response. I think it’s good to get different takes once in a while, ruffling feathers is a good way to get the conversation going. I too come here because Mark’s evenhanded and reasonableness, I’ve noticed that some later postings take a slightly different position in the light of new research than his older postings on the same topic, and that proved to me that his message is based on science and not a set in stone opinion. Anyway, looking forward to the follow-up Mark.

how come strawberries, blueberries, avocado or other fruits werent used as examples of fiber vs. sugar content?
they have a lot less sugar and so do veggies.
Never thought of fiber content before so it is an interesting read

Dear Mark, Thank you for continuing to question dogma in all it’s forms and so generously share your investigations. I ran across this article over the past couple days in a quest for information on a totally different topic and ordered the author’s book, Fiber Menace. I am looking forward to reading about his work in more depth. I truly believe that questioning my very well-intentioned doctors, reading far outside the MSM, and finding reliable sources to educate myself about living my healthiest life have saved me from continuing down a very unhappy and unknowingly self-destructive path. I admire you, trust you and truly thank you for your dedication to improving my life and the lives of so many others. In my case, I think the often overwhelming, but very fortunate, news is once you start to question, you can never stop. Thank you again. XO, Ann

I never did buy into the need to supplement your diet with any kind of added fiber products. My intuition has always been that these products can scrape and cause more harm than good. I eat plenty of vegetables and a little fruit, take some probiotics and enzymes, and my digestion and regularity is great. Again, as so many have commented, eating whole foods, a grain-free primal diet, will get the job done just fine, no need for harsh fiber supplements.

My attention was lost with the quote:
“a moderately active adult can utilize no more than about 200 grams of carbohydrates per day without encountering a scourge of the inevitable obesity, prediabetes, or diabetes.”

That is a ridiculous assertion to make and one that requires seriously strong evidence.

Ben, its not ridiculous, you’re just under informed. There are reams of research papers done on carbohydrate demand. google “glycogen demands of exercise” , “daily glycogen demand sedentary”. Observe those around you who don’t exercise and watch how easy it is for most people to get REALLY fat when consuming 200gms of carbs a day. If you’re not incredibly active then those carbs aren’t utilized and things happen. Just because you don’t know about it doesn’t make it false and no one needs to spoon feed you references. Dig deeper, this is basic stuff.

You lost me at:
“It‘s not surprising that so many Americans are suffering from the ravages of diabetes and obesity”
As if those problems all spring from eating too much fruit and vegetables and not fast-food, fiber-less white flour and sugar in all forms.
And that’s only the tip of the iceberg when it comes to this article, as many have previously pointed out, so I’ll leave my comment at that…
Can’t wait to read Mark’s reply!

Both. Once any food is consumed and digested, your blood has no idea about its original sourcing. All it will “see” is fats, proteins, and sugars. Fat foods are more offensive than fruits simply because you can eat more of them in a single sitting, and wash them down with soda and shake.

I fail to see how fat is the offender here. Also if you “wash all your fats down with a soda and a shake”.. well thats not really the same thing as having a cup of strawberries for desert, is it? Typically if you eat to satiety with a lot of fat then you wont feel the need to wash it all down with a soda and a shake. The only people who do this are either really fat, in a fat gaining trajectory or someone who is just really hungry.

Fat foods are more “offensive” in what regard? To gaining body fat? Again, its the carbs from the soda and shake, not the fat, that is throwing a wrench in things. Your logic is putting Fruit on one side and Fat combined with soda and shakes on the other. That doesnt make sense to me.

Im arguing here from an experienced based model, not just something Ive read.

I am SO glad to see the facts around Kellogg’s disgusting and bordeline psychotic mutilation of children being shown to a wider audience, since the motivation behind his promotion of cereals as a go-to morning food sprang directly from his sick ideologies.

His life’s work was based on a pathological hatred of sexuality, and yet to this day the ideas he founded are a primary part of the sanctification of cereals as a product in their own right, rather than in bread to mop up real foods like butter or gravy, or as an ingredient in cakes or sauces.

I’ve been trying to tell my overweight friends & colleagues who struggle with constant hunger while loading up on “healthy, filling” cereals about him for ages, because his story is an important part of debunking the wholegrains myth, and often getting weird looks that I should think such a “great” man was so evil, and now I thankfully have this link to send them!

Mark, I am hoping you will devote a whole post of your own to all this – I am pretty convinced by this myth-busting, but also curious where cooked veg have a place, curious about what scientists like Phinney and Volek might have to say about it… Thank you!

Hey Mark!
Just wanted to say you’re brilliant! Testing out this ridiculous information on your audience by having a guest post it- that way you can find out just how much BS your readers are willing to buy without having to take the fall!

“…….. decline of libido and infertility are among the very first symptoms of malnutrition prevalent among ardent vegans.” ——————- That’s weird. About a month after switching to a strict vegan diet, my libido went through the roof and hasn’t slowed down since (going on 9 months now). Can’t speak to the fertility issue though.

So, as you can see, even the foods that are considered fiber-heavy, such as broccoli or carrots, are pretty moderate. So if you eat almost 2 lbs of the above vegetables, you still will get only 12.4 grams of fiber.

That’s why I don’t say anywhere that you shouldn’t eat vegetables, and I do prefer vegetables to fruits because they contain significantly less sugar.

Isn’t the fiber in fruit and vegetables structured differently then added fiber (e.g. cereals)? Natural fiber in fruits and vegetables surrounds sugar, slowing its absorption into the bloodstream, while added fiber will just clear out the gut. There is a big difference between eating a piece of fruit and consuming a cereal with added fiber.

That is not true. Fiber is fiber, regardless of its source. That said, you’ll get more damage and faster from bran-fortified cereals simply because a single serving of cereals may contain more fiber than 5-6 fruits or vegetables.

I read Fiber Menace some years and found some of the suggestions helpful and some questionable. I am 60 now and have been trying to achieve healthy regularity for most of my life with inconsistent results. I’ve tried high and low fiber regimes and with all the issues that can be named.

So my 40 years of experiments has led me to – some fiber from non starchy veggies like broccoli, cauliflower, cabbage, brussel sprouts, plus various nuts like macadamia, and almonds, and plenty of fat especially animal fat. Adequate hydration is essential but diverting fluids to the bowel rather than the bladder requires some assistance and the magic agent for that is magnesium. The fat stimulates bile and more bile appears to lead to a trigger for stronger peristalsis. And it is that action that should be encouraged to propel food and waste materials through our digestive tract, not bulk and gravity.

It takes some experimentation on dosage but this mineral in the correct amount, combined with the other listed components seems to give quite consistent and reliable results. You’ll need to experiment to discover optimum dosage, you’ll very quickly discover if you have overdone it

You will get some from many whole foods but it doesn’t seem like enough for many people and especially on vlc and Atkins type regimes. Magnesium deficiency also results for many in severe muscle cramps, something mentioned in one of the Atkins books with the comment that it didn’t know why. I have had such cramps for decades and magnesium has resolved that completely.

Very high dosage will likely result in explosive results, so go easy at the start. as your body becomes more accustomed to higher levels of magnesium you should find a high degree of consistent results. I have found around 1.5g/day of magnesium citrate works for me, taken half in the evening and half in the morning.

It also seems that magnesium is involved in a large number of biochemical activities so this supplementation seems like an all round winner, and without any of the damaging and harmful affects of bran and other artificial forms of fiber.

So magnesium, modest natural fiber that most likely Grog would have consumed, quality animal fat, and good hydration. That package seems to work well for me at least.

I have experimented with pre and pro-biotics but that always felt like an unnatural process that shouldn’t be needed if we are consuming whole natural foods.

Fiber Menace was one of the first books I read a few years ago, when I realized that everything I thought I knew about nutrition was wrong. Following Konstantin’s advice, along with daily Metamucil, I eliminated the gut pain I’d been experiencing most of my life (as I swung back and forth between diarrhea and constipation) and learned what it was like to be regular. I also said good-bye to volcanic heartburn within a few days and discovered more of the wherefore.

I still eat veggies and enjoy fruit in moderation, but if I’m not that hungry and the veggies or salad don’t look as appetizing as the steak or pork chops on my plate, I don’t force myself to eat the former for the sake of the fiber.

I admit that fiber is way over rated, especially the kind of fiber CW usually touts – that from bread, psyllium, fruits, and bulking agents. However, this article came off almost as if the author was suggesting we go as low fiber as possible. Sorry, but that’s not ancestral diet style.

The lack of comments about fiber from vegetables was noticeable. I eat green leafies a lot, and get about 20-30g fiber per day from them. My regularity is far better now than when I ate the SAD. I also feel fuller when I eat veggies. While we obviously shouldn’t treat fiber as a magic bullet, the “demonization” of it by this author seems quite unnecessary.

Also, I wonder what types of fiber all these studies used? What lifestyles and preexisting conditions and medications did the subjects have? What about fluid intake and activity? Studies can be misinterpreted, as we all know. I’m not going to look up all these studies, but I’d bet the subjects aren’t Primal Beasts.

I tend to agree with the general thrust of the article as I understand it. You don’t need to go out of your way to get fiber—just eat real food. Fortunately, TPB accomplishes that.

That said, I think the author has not integrated a lot of research on the brain / gut connection and also resistant starch. RS in particular is quite interesting. Hundreds of studies going back 30 years.

Some benefits:

1. It’s starch, but it won’t raise your BG even with significant doses of say, 30g.
2. It’s starch, but if consumed in conjunction with a rapidly digesting starch (like a baked potato) your BG spike will be greatly less.
3. #2 carries over even to the next day, blunting BG spikes after meals (called the “second meal effect”).
4. Even a dose of 30g won’t knock you out of ketosis.
5. Not only does RS resist digestion so that it can get to your colon (and all the way down, where most cancers originate), but probiotic bacteria in a meal, supplement, stomach or small intestine can hitch a ride on the RS granules and be protected from getting killed off before getting to the colon where they belong.
6. You don’t actually digest resistant starch (this is why it won’t raise your BG), your gut bacteria do and guess what the by-products are? Short chain fatty acids (saturated fat). This is what helps blunt the glucose spike of other foods and subsequent meals.

I’ve had a number of both T1 and 2 diabetics report to me that since supplementing with some RS (very cheap), combined with eating foods known to contain RS cold (this greatly increases levels from when hot, which destroys RS), they have achieved much improved BG control and have been able to reduce insulin dosage.

Anyway, I’ve been doing a series of posts on it and in fact, those post were mentioned and recommended by Chris Kresser in a recent podcast. For anyone interested, here’s a link to one of the last posts, which is a comprehensive list of foods that contain RS and quantities. There’s also links to all my previous posts, including a couple that list tons of research.

@Konstantin, I am open minded. In fact enough to give your opinion’s some thought and questions. So gut flora don’t need to be “fed” and can live on mucus? OK, I’ll bite. What part of the mucus? Is it the oligosaccharide carb’s in the glycoproteins of the mucus? If not, how is the mucus feeding the flora? And if this is THE major source of food for the flora wouldn’t that hurt the mucus’ primary task of protecting the mucus membrane and epithelium, lubricating the intestinal tract so food can pass? I presume this glycoprotein serves some purpose (water retention?) other than feeding flora. I’m all ears if you’d like to explain.

i’m so confused!! all i know for certain is that if i skip my heaping teaspoon of psyllium powder with 16 oz of water one day, i probably won’t poop the next day, and even if i do it’ll be hard, big, and incomplete. i’ve dealt with constipation since i was a teenager (i’m 47 now). from my early 20s until about 2 years ago, i ate prunes everyday so that i’d poop everyday. i only switched from prunes to psyllium when i decided to lower my carb intake.

I discovered Konstantin’s site and read every page on it, and his book as well. Yes, his tenets fly in the face of Common Wisdom, and ruffles many peoples’ feathers. But if you are interested, please read his site – even without buying his book, the site has every point covered in the book in detail.

I went Paleo over two years ago, and discovered Gutsense.org soon afterwards. Much of what he writes about made so much sense to me that I decided to change and refine my diet even further.

As a middle-aged woman, pre-Primal, I experienced many of the issues Gutsense describes as originating in excess fiber. Going Primal helped some of those issues – a lot, but getting rid of the excess fiber and fiber-minded dietary habits and occasional supplements took me to complete digestive health.

As we can see here, Konstantin’s balls-out, take-no-prisoners style of obliterating the Common Myths about fiber in our health industry can rub people the wrong way. He is not as refined and measured as Mark Sisson (who is?). But don’t throw out his ideas because his delivery hits you over the head. There is plenty of life-changing info on his site and in his book. I know many folks with chronic digestive issues that would be mostly healed by a combo of going Primal and lessening dietary fiber. It is a greatly needed revolution!

The Primal Blueprint Podcast

Interviews with Mark Sisson and other health experts. Audio versions of select Mark’s Daily Apple posts each week. “Best of MDA” recordings. Fresh, lively content to help you stay at the cutting edge of Primal living!